Pressure-sensitive papers with adhered polychlorobiphenyl (PCB) and other degradation-resistant organic chlorine compounds (hereinafter PCB etc.) remain in storage for the lack of a safe process for treating the pressure-sensitive paper. On the other hand, methods for draining transformers, oil capacitors and other electrical equipment of PCB etc. and then washing them with a solvent such n-hexane are being promoted. However, removal of PCB etc. adhering to the paper, wood and the like incorporated in such electrical equipment and the like is extremely difficult and no safe treatment process for this purpose has yet been discovered.
Since n-hexane and other such solvents have low viscosity and are excellent solvents of PCB etc., the ordinary washing operation is highly effective for washing metals, plastics and the like, only requiring that care be taken regarding the low solvent ignition point. PCB etc. remaining after recovery of n-hexane or the like from the washing solution can therefore be safely and completely broken down by the method under the inventors' earlier application (Japanese Patent Public Disclosure Hei 7-8572). However, a treatment process using n-hexane or the like cannot completely extract and break down PCB etc. adhering to paper, wood or other such materials containing cellulose.
The object of this invention is therefore to provide a washing and removal process which completely extracts and breaks down PCB etc. from a cellulose-containing material having adhered PCB etc.